Mercedes-AMG SL 63 (R232)

A different kind of SL

The R232 SL 63 is the first SL developed by AMG rather than Mercedes-Benz's own passenger-car division. It arrived in 2022 with a 4.0-litre twin-turbo V8, 585 bhp, a nine-speed multi-clutch transmission and standard 4MATIC+ all-wheel drive. It is a two-plus-two roadster with a fabric roof, and it is much more aggressive to drive than the SLs that came before it.

That sounds like a winning formula, and on paper it is. The SL 63 covers ground at an alarming rate, the V8 makes a proper noise and the roof folds in about 15 seconds. The interior is luxurious, the seats are comfortable and the car has enough driver aids to make a long journey relaxing. It is a grand tourer with a muscle car streak.

The problem is that the SL sits in an awkward place. It is not as sharp as a Porsche 911 Cabriolet, not as spacious as a BMW M8 Convertible and not as exotic as an Aston Martin Vantage Roadster. It is also very expensive when new, which means the used market is where most buyers will meet it. That is good news for a first owner's loss and bad news for anyone who buys at the top of the curve.

Running costs

Mercedes-AMG service intervals are typically 12 months or 10,000 miles, whichever comes first. A minor service at an independent specialist is £700 to £1,000, and a major service with plugs, filters and fluids is £1,200 to £1,800. Main dealer prices are higher. The V8 is not especially fragile, but it is tightly packed and access is not cheap.

Tyres are a significant cost. The SL 63 runs 20-inch front and 21-inch rear wheels on most cars, and a set of premium tyres is £1,200 to £1,600. The car is heavy, so rear tyres wear quickly if you use the performance. Brake discs and pads are £2,000 to £3,000 for the standard steel system. Carbon-ceramic brakes, if fitted, are much more expensive to replace and should be inspected carefully.

Fuel consumption is what you would expect from a 585 bhp V8. A steady motorway run can return high 20s, but town driving and enthusiastic use will be in the mid-teens. Insurance and road tax are substantial. This is not a car to run on a tight budget.

Roof and electrics

The fabric roof is the SL's defining feature and its biggest risk. It is a complex assembly of motors, sensors, hydraulic or electric actuators and seals. It should open and close smoothly, without hesitation, grinding noises or warning messages. Check for water ingress around the windows, the boot and the rear quarter panels. A leak can damage the electronics under the seats and in the boot.

The SL is also densely equipped. Check the MBUX infotainment, the digital instrument cluster, the Burmester sound system, the climate seats, the driver assistance systems and every camera. Battery drain is a common complaint on cars that sit for long periods. A trickle charger is a sensible accessory, but it should not be used to mask a failing battery or a parasitic drain.

The MCT transmission can be jerky at low speed, especially when cold. Some of that is characteristic of a multi-clutch gearbox, but a car that clunks or hesitates when selecting drive should be checked. The 4MATIC+ system adds another layer of complexity, and a warning light or a shudder under acceleration is a reason to walk away.

What goes wrong

The M177 V8 is a strong engine, but it has known weak points. Check for oil leaks around the turbochargers and the valve covers, coolant residue around the heat exchanger and the water pump, and any rattle from the turbo wastegates. The engine mounts can wear, and the active engine mount system can produce vibrations. A cold start should be smooth, with no long cranking or blue smoke.

The SL's air suspension and adaptive dampers are another area to inspect. A car that sits unevenly, makes knocking noises over bumps or shows a suspension warning has a potentially expensive problem. The optional rear-axle steering is durable but should be checked for play and warning messages.

Brake squeal is common on AMG cars, especially with the high-performance pads. It is not necessarily a fault, but a car that pulls to one side or has a soft pedal should be inspected. The same applies to the tyres: uneven wear can indicate alignment or suspension damage.

Buying checklist

Ask for the full service history and check that the running-in service was done on time. Mercedes-AMG engines have specific oil and filter requirements, so look for invoices that show the correct specification. A car with a gap in its history is a risk on a complex V8.

Check the roof operation from cold and from hot, and inspect the seals and the boot floor for water. Test every electrical function, including the seats, the steering wheel controls, the head-up display and the parking cameras. A battery health check is worthwhile. Look for paint repairs on the bumpers and the rear arches, and check the wheels for kerb damage and cracks.

A pre-purchase inspection by an AMG specialist is essential. The SL 63 is not a car to buy on a quick test drive. The specialist should check the engine for leaks, the transmission for fault codes, the suspension for wear and the roof for alignment. Budget for a diagnostic scan, not just a visual inspection.

Market and depreciation

The SL 63 has depreciated heavily. Cars that cost £150,000 or more when new were trading at £90,000 to £115,000 for 2022 and 2023 examples at the time of writing. Later, low-mileage cars were £110,000 to £130,000. The SL 55 is cheaper, but it does not have the same V8 character or the same performance.

The depreciation is the main reason to buy used. The first owner has taken the biggest hit, and the car is still under manufacturer warranty for part of its life. A car with the optional AMG Dynamic Plus package, carbon-ceramic brakes and a desirable colour will hold value better, but the SL is not a limited-production car. Expect further softening as more cars come off lease.

The SL 63 is also competing with the Porsche 911 Cabriolet, which holds value better and has a more focused chassis. That does not make the SL a bad car, but it does mean you should buy it because you want the V8 and the roof, not because you expect it to appreciate.

Who it suits

The SL 63 suits someone who wants a fast, comfortable open-top grand tourer with a V8 soundtrack and a luxurious interior. It is good for long weekends, coastal roads and the occasional commute. It does not suit someone who wants a track car, a cheap-to-run sports car or a strict two-seater with a manual gearbox.

If you want the SL experience with less complexity, the SL 55 is worth a look. It has the same basic car with less power and a lower price. If you want more drama, an Aston Martin Vantage Roadster is more exotic, but it is less practical and more expensive to maintain. The 911 Cabriolet is the safer choice for resale and reliability.

Alternatives

The Porsche 911 Carrera Cabriolet is the obvious rival. It is smaller, sharper and more reliable, and it holds value better. The BMW M8 Competition Convertible is faster in a straight line and more spacious, but it is heavier and less charismatic. The Aston Martin Vantage Roadster is more beautiful and more exclusive, but it is a two-seater with a smaller dealer network.

The Mercedes-AMG SL 55 is the value pick in the range. It has 476 bhp, the same roof and most of the same equipment, and it costs less to buy and insure. If you do not need the full 585 bhp, it is the sensible choice. The SL 43 is cheaper still, but it uses a four-cylinder engine and does not feel like a proper SL.

How this review was compiled

This review draws on Mercedes-AMG's published technical and service information, owner reports from MBWorld and AMG Private Lounge forums, UK specialist servicing guides and current Auto Trader listings. Indicative UK prices vary with specification, mileage and condition.